In this application, the terms "substrate" or "printing substrate", without further specification, include any substrate on which printing is effected, regardless of its form and composition, be it e.g. uncoated or coated paper, plastic or any other sheet material, or a page of a booklet or other bound object intended to carry printing on pages or other parts thereof. The terms "picture" or "image" or "subject matter", as used herein, synonimously indicate any kind of printable or printed subject matter, and therefore comprise, among other things, pictures representing persons or objects, portraits, photographs, letters, words, signs, signatures, data, and any figures or images or graphic symbols that may be carried by a substrate of any kind. In many cases to which this invention is applied, the picture comprises a portrait of the owner of a document and words, numbers and the like, that contain information relevant to the identity of said owner and to the character, validity period, and other features of the document itself.
Graphic matter printed on passports, identifying cards and like documents, generally includes identifying photographs, particularly color photographs, accompanied by identifying data. For this purpose, the laser printing process and laser printing machines are widely used.
Basically, the laser printing process comprises, as a first step, defining the subject matter to be printed in the form of an array of signals that can be used to control the printing machine. A common way of doing this consists in capturing the subject matter to be printed and registering the results of the capturing in a processor's memory, in the form of an array of digital signals. Said signals control the emission of laser rays from a laser source. The laser beams impinge on a cylinder in a pattern controlled by the said signals and electrostatically charge the surface of said metal cylinder at selectively predetermined spots. The selectively electrostatically charged cylinder passes in the vicinity of a reservoir of coloring matter in powder form. The coloring matter particles are attracted to the aforesaid selectively charged spots of said cylinder and form thereon the desired pattern. A print substrate is then passed into contact with the metal cylinder and the pattern formed by the color particles is deposited thereon. This operation is repeated for each color if a multicolor print is desired, usually four times to provide the basic colors magenta, cyan and yellow plus black (black will hereinafter be considered to be a color), to produce a complete color image. At this stage a colored image has been formed on the print substrate. In order to stabilize the image, the print substrate is passed between heated rollers, which fix or set the print so that it is permanent and stable.
This process is quite effective for a number of applications, but it encounters difficulties, hitherto unsolved, when it is necessary to print on a substrate that is not in the form of a free sheet, but is in bound e.g. in the form of a booklet or a pouch, typically a passport or similar bound document. It would be highly desirable to print on a passport or like document, after it has already been bound in booklet form, the passport holder's photograph, signature, and/or other printed information. However, this is not possible with conventional color laser printing techniques. Other difficulties would arise, should the print substrate have a surface which is not absorbent with respect to the colors: the coloring matter is then partly if not totally transferred from the print substrate to the heat-setting rollers.
Pending U.S. patent application Ser. No. 08/398,642, filed on Mar. 3, 1995, describes and claims a method for printing on substrates in booklet form, which comprises the following steps:
1--providing a set of instructions, which reverses the original subject matter to be printed to define a reversed subject matter file; PA1 2--providing a temporary substrate, the surface of which is substantially non-absorbent and non-adhesive for the coloring matters to be used for the printing; PA1 3--depositing on said temporary substrate coloring matters, whereby to form thereon said reversed subject matter, by the appropriate steps of the conventional laser printing method; PA1 4--provisionally setting said reversed subject matter by radiant heat; PA1 5--juxtaposing said temporary substrate face-to-face with the final printing substrate; PA1 6--transferring the reversed subject matter from said temporary to said final substrate, whereby said reversed subject matter is reversed and reproduces said original subject matter on said final substrate; and PA1 7--setting said reproduced original subject matter on said final substrate by the application of pressure and optionally heat. PA1 a--providing a set of signals--particularly digital signals, such as a computer file, a frame grabber, a memory buffer or the like--defining subject matter to be printed on the document (which will be synonimously called hereinafter "the picture" or "the image" or "the original picture or image" or "image file"); PA1 b--providing a temporary or intermediate substrate, preferably a substrate the surface of which is substantially non-absorbent and non-adhesive for the coloring matters to be used for the printing or at least is considerably less adhesive and/or absorbent for said coloring matters than that of the transparent substrate, mentioned hereinafter; PA1 c--depositing on said temporary substrate coloring matters, whereby to produce thereon said original image, by the appropriate steps of the conventional laser printing method; PA1 d--provisionally setting said image, preferably without the application of pressure, and more preferably by radiant heat or dielectric or microwave heating; PA1 e--juxtaposing said temporary substrate with its face carrying said image in contact with the rear face of a transparent substrate; PA1 f--transferring said image from said temporary substrate to said transparent substrate, whereby the said image is applied to said transparent substrate rear face and is visible, in normal form, through said transparent substrate from the front face thereof (and would be seen as reversed from the rear face thereof); PA1 g--removing said temporary substrate; and PA1 h--binding said transparent substrate to other components of the document to be produced. PA1 juxtaposing said transparent substrate to the final substrate that is intended to carry the image, with the rear face of said transparent substrate in contact with the front face of said final substrate; and PA1 8--hot and/or cold laminating said transparent substrate in contact with said final substrate, permanently to bond them, whereby said image becomes enclosed in the laminate and visible through said transparent substrate as if printed on said final substrate. PA1 providing a card blank (pouch) which comprises a front and a back sheet or leaf having the desired shape and dimensions, at least the front leaf being transparent and the back leaf being transparent or opaque, the two leaves being connected in fixed positioned relationship, preferably by being joined along a very narrow strip on one side by lamination or adhesively or in any other convenient way. PA1 laminating said front and back leaves, whereby to produce a card, wherein said image is visible from its front face.
Said process, however, is difficult to carry out and does not provide the desired printing quality, whenever the final substrate does not have a surface that is fully suitable for receiving the reproduced original subject matter and permitting it to be set thereon. This occurs relatively often when said substrate is part of a booklet, particularly a passport, and more particularly when the print is to be effected on the inside of a booklet or passport cover. The cover must have a certain stiffness and is made of a material which possesses it, and, even it is covered by a sheet of paper adhesively connected thereto, its surface irregularities render it unsuitable as substrate for the aforesaid or other known printing methods. On the other hand, printing on the inside of the cover may be preferable or even necessary when the inner sheets are too light or otherwise unsuitable for printing pictures thereon.
On the other hand, identity cards, passes, and the like are prepared, according to the art, by providing a front and/or a back sheet, the front sheet at least being transparent, inserting between them a third sheet, bearing the desired printed matter--photographs, words, numbers and the like--joining the front and back sheet together by lamination, thus sealing the printed sheet therebetween, and trimming the resulting laminated card to the desired contour. This method of production has several drawbacks. Firstly, the final lamination requires that the printed sheet be smaller than the final card, in order to leave a sufficiently wide margin on all sides of the card, along which the front and back sheets are laminated together. But, as a consequence, either the card is unnecessarily large or the printed area is unnecessarily limited. Secondly, said method requires a final trimming, since it is impossible to assemble with sufficient precision the sheets to be laminated. Finally, the presence of an intermediate sheet between the front and back sheets makes it possible, in many cases, to disconnect the said layers sufficiently to reach said intermediate sheet and alter or counterfeit the printing it bears.
It is a purpose of this invention to overcome the drawbacks of prior art methods and efficiently and economically to produce documents, in particular identification documents both in bound and in card form, such as passports and the like or identity cards and the like.
It is another purpose of this invention to make it possible satisfactorily to print subject matter, including multicolor subject matter such as data and photographs, on substrates that are part of booklets, particularly of passports and pouches, and the like.
It is a further purpose of this invention to provide a method for printing subject matter, including identifying data and photographs and the like, on the inside of the covers or on any other page of bound substrates, such as passports and the like.
It is a still further purpose of this invention to provide an apparatus for achieving the aforesaid results, which apparatus is simple and not expensive to make nor difficult to use.
It is a still further purpose of this invention to provide a new and improved method for the production of identity cards, passes and the like, that is free from the drawbacks of prior art methods.
It is a still further purpose of this invention to provide such a method that does not require a trimming operation.
It is a still further purpose of this invention to provide such a method which permits to fill almost the entire surface of the card with information.
It is a still further purpose of this invention to provide an identifying document, in particular an ID card, that cannot be separated into component layers, for purposes of altering or counterfeiting its content.
It is a still further purpose of this invention to provide such a document, in particular an ID card, in which practically the entire surface bears printed matter, such as photographs, words, and other information.
It is a still further purpose of this invention to provide an identifying card or the like that is completely transparent, and therefore is difficult to counterfeit.
It is a still further purpose to achieve the aforesaid purposes by applying a modified laser printing method.
Other purposes and advantages of this invention will appear as the description proceeds.